Tolkāppiyam

Tol (தொல்) means Old and Kappiyam (காப்பியம்) means a literary work.
The name of the author could not be identified (usually referred as Tholkappiyar) and the work apparently relates to Grammar in Tamil.
It is learnt that the author was one of the 12 disciples of Sage Agastya the Father of Tamil Grammar. This sage was living in the south near Madurai, during the visit of Lord Ram to the south in search of his wife, abducted by the Lankan King Ravan.
The age of Lord Ram precedes that of Lord Krishna and hence the work can safely be said to precede 3000 BC (the ideal period of Mahabharat Yudh).
Lord Shiva and his Son Murugan is said to have laid the first tenets for the Tamil Language, probably long long time before sage Agastya could compile the same.